Center image placement with Vantage/Spire/Summit

[daveneumann]

I was just curious about where others are experiencing center images such as female and male vocals, centered instruments, etc. Are these images typically recessed or do they project forward in front of the plane of the speakers.

In my system, center images are typically 2 - 4 feet behind the plane of the speakers and I have never experienced imaging that projects in front of the speakers from my Spires.

The reason I am asking is that I am corresponding with someone about system set up and he maintains that getting center images to project in front of the plane of the speakers leads to richer tone, more harmonic density and an overall more involving sound.

Is anyone getting this kind of imaging with their Logans? If so, can you please share a little detail on set up?

Thanks!

 

[FISH_MAN]

I am not sure what phenomenon precisely contributes to center imaging to begin with but if you could imagine a giant football with the tip pointed at you and the body if it between the speakers this could represent the body of sound I get from centered instruments and female voices.

 

[daveneumann]

Thanks Fish...

That's an interesting word picture of a big football of sound! How far out do you have your Spires from the front wall? Are you using any absorption or diffusion behind the speakers? How much are they toed in?

Thanks,

Dave

 

[FISH_MAN]

the panels are a little more than 3' from the back wall probably 3.5' feet. they are toed in to the flashlight trick suggested by martin logan in their manual and there is diffusion panels " q fusers " behind them.

 

[Gordon Gray]

Dave,

Here's my take.

Others who have done more "hardware swapping" than I will hopefully chime in but my sense is that different electronics will project different layers of dimensionality. This would be in all three planes.

Jeff would be someone who might offer some insight on this issue.

Also, I've noted in my system that the loudness level seems to have an impact on this phenomena. The louder, the more forward at the expense of decreasing the "depth" heard in a recording.

I have also noted, since I plugged my amp into the wall outlet versus the PLC, the the overall dimensionality is more "naturally" layered, especially in the front to back perspective.

I've had gear in the past, where the imaging was so far back from the front speaker plane, the overall presentation was less dynamic and less involving.

Some equipment reviews will use a "seating" analogy when you attend a live classical concert to describe this. An example would be a seat "f" perspective versus a seat "n" position with the former having a more "up front" experience versus the latter.

Since I listen mainly to classical music, it is surprising how recordings vary in their ability to "layer" the various instruments. Regarding most popular music, who knows what they do and the final result thereof. I've also noted substantial differences in this type music.

If you want to test your system within the context of its ability to properly layer the soundstage, a well recorded classical CD or record (full symphony) will allow you to better determine its performance.

Hope that helps.

GG

PS: Panel front to back wall is 5'.

PPS: I believe the goal of any audio system is to allow the listener to hear the "recording venue acoustic". Once you are there, there's not much else you can expect from your system in resolving the dimensionality performance issue. Mine still falls short of this mainly because of the size of my room. Having said that, I keep getting a bit closer as time goes on.

 

[daveneumann]

Thanks Fish and Gordon. I appreciate the quick input.

Gordon, I think you are spot on with your comments about different gear. In particular, I've experienced a different presentation with tube amps.

I also agree about loudness, with higher volumes projecting images out in front more. Another thing I have found is that when all the lights are off and my listening room is dark, the center images seem to be more present and less recessed.

And you got me thinking about my amp which is plugged into my power conditioner. Tomorrow I'll try it directly into the wall to see what that does.

Thanks for the advice guys.

Dave

 

[kach22i]

I recently played with the vertical angle of my speakers, and it seems to be the largest factor followed by acoustic treatments and then electronics & tube selection.

The nearer to true straight up and down (vertical angle), the more forward the center image (but shallow/less depth).

The more angled back, the farther the center image is (and with lots of depth).

 

[FISH_MAN]

I like my speakers angled the way logan made them from the factory I tried it some different ways for a while but am now back to the factory settings.

 

[CCH]

In my system, center images are typically 2 - 4 feet behind the plane of the speakers and I have never experienced imaging that projects in front of the speakers from my Spires.

My setup produces a similar center image, although I'd say that two feet back is typical. To be honest, the single most attractive feature of my Summits is the depth, complexity and dimensionality of their center image, especially on well recorded vocals. It is the one thing that everyone notices and comments favorably on. I have had many, many speakers over the years that projected a more forward center image, but none of them sounded anywhere near as realistic and involving when reproducing the human voice. I'm not sure I'd want it to be different, although it would be interesting to hear the difference on this system.

I, too, have tried again and again to adjust the rake angle of the speakers based on recommendations from other users on this site. I have always returned to the factory default as the most satisfying arrangement. Of course, that has everything to do with my particular room (etc.); I trust that others are equally justified in their choices.

 

[sleepysurf]

With my Summit setup, the image is also 2-4 ft behind the plane of the speakers. Years ago, when I had a pair of Apogee Stage's, the image was, indeed, projected ~2 ft in front of the plane of the speakers, and my recollection was that it sounded more realistic and "live" than I have now. However, that was 20 yrs ago, with different gear in a smaller room, so not really a fair comparison. I've yet to hear an ML setup yet that projects the soundstage that far forward.

 

[kach22i]

If you don't want to mess with the angle of the speaker, I have found that putting something absorptive dead center on the wall between the speakers (the front wall you look at) helps flesh out the center stage and project it forward a bit.

I have also found that moving the absorptive panel off the front wall toward you moves the center image towards you.

My experiments were confined to the area above my large CRT screen TV, but I suspect this acoustic phenomena would apply to a more normal setup.

Before (recessed center stage):

After (forward center stage):

I plan on adding a 20"x30" black foam core board behind the waffle foam and see if that affect more frequencies and the corresponding center image.

 

[Victor]

Dave,
My system's presentation matches yours, but I too have found the volume control useful for fine tuning. My Vantages are approx 5ft out. Purely based on what members have said over the last few years, the impression I get is that those who've positioned their speakers closer to the wall seem to enjoy more forward projection.(???) I also concur that what's in between your speakers can dictate the centre balance in relation to the L and R wings. Just moving your TV (if this is the case) a few inches backwards/forwards/vertically can be significant as indeed is the angle of it relative to the speaker plane. A small offset angle can be very helpful.
Hope this helps..........................Victor.

 

[Gordon]

In my case, it depends on the recording and volume. Most music is right at the plane or slightly forward of the speakers with layering going back quite deep. The few pieces I have that bring the voice forward of the speaker about a foot. At low level the affect is not as pronounced. At higher levels, perhaps my gear is waking up and exciting the room a bit more thoroughly.

Speakers are vertical with very little toe about 5 ft off the front wall. I did not seem to obtain this noticeably deep layering until I changed my pre, so I'm certain that the choice of gear has an impact on it as well.

Gordon

 

[sleepysurf]

If you don't want to mess with the angle of the speaker, I have found that putting something absorptive dead center on the wall between the speakers (the front wall you look at) helps flesh out the center stage and project it forward a bit.

I have also found that moving the absorptive panel off the front wall toward you moves the center image towards you.

I conducted a recent test of the impact of a large HDTV placed between the speakers, and (not really that surprising) found out the impact is minimal (at least in my setup).

I have a 55" LCD TV on a cantilever mount, which allows me to push it in (almost) flush with the wall, or pull it out 2+ ft, as well as rotate it (up to 45 degrees) to one side or the other. I recently hosted a local audio society listening session, and we spent a few mins (blinded listeners) asking them to judge the impact of the TV's location on the soundstage. Fact is, it made little difference, and the listeners could not even tell when the TV was turned the full 45 degree angle to one side or the other (which theoretically should have greatly shifted the image). I have conducted similar (non-blinded) tests (and measurements using XTZ) on my own, and reached a similar conclusion.

The reason that such a large reflective surface between these speakers has minimal impact, is simply due to the dipole nature of electrostatic panels. The front and back "figure 8" radiation pattern of ESL's means there is minimal lateral dispersion, so a large centrally placed reflective object (TV or cabinet) does not cause as much reflection or interference as one might expect. That's not to say it doesn't have any impact, as it clearly does, and I strongly agree that no large object between the speakers would be ideal. However, for those of us with room/WAF limitations, there are other more important acoustic variables (speaker distance in front of wall, rake angle, absorptive vs. diffusor treatment behind speakers, bass trapping, etc.) that actually play a bigger role in soundstage/imaging.

I sometimes cover my HDTV with absorptive acoustic material, but likewise found (and measured) that all it does is slightly attenuate the midrange/high SPL's (1-2 dB per XTZ), slightly rolling off the highs (much like tubes). It sounded better at first, but after a while, I missed that "live" presence. Conversely, I found that placing absorption panels behind my HDTV actually had greater impact! That too, makes sense, as what (little) laterally dispersed soundwaves head back towards the TV, are more likely to "bounce" between the wall and rear of the TV (if there significant space between the two), thus causing a slight "echo" effect which "smears" the image. Unfortunately, I can't measure that effect with the XTZ analyzer. I ended up cutting out some panels to fit around the cantilever mount, and hung them on the wall behind the TV.

Bottom line, IMHO, is don't fret too much about having a large TV between your speakers. It's still possible to have a precise and deep soundstage if you pay attention to the other details.

 

[JonFo]

Alan, congrats on a well written, and accurate post. You nail the most important aspect to imaging on ESL’s: which is their interaction with the room, and how the rear wave reflections are handled.


Imaging on dipoles is hugely impacted by what is happening to the rear wave.

Think of it this way, if monopole speakers are sensitive to toe-in and height of their tweeters, then imagine how much more difficult it would be if you strapped two monoloples back-to-back and tried arranging *that*.

ESL’s are just like that, they radiate 100% the same energy front and back, and out of phase.

So ‘imaging’ is all about placement and room integration.

From my research, one gets incredible imaging if the rear wave is correctly managed, which for me has been to dampen it substantially.

Even with a large sub/center speaker between the L/R, my 2ch imaging is between the speakers, and depending on recording and mix, the soundstage envelops the listeners. Occasionally, it’s uncanny, but I’d swear it was a multichannel album, and when I check to make sure I don’t have some ‘mode’ on, it was just a really good 2ch mix.

Daveneumann, To your main question: yes, I have recordings where the vocals will appear to be in-front of the speakers. The Dead Can Dance SACD re-issues will have that effect on some songs.

One of the things that ‘pulls’ the image behind the speakers is the delayed rear wave (remember, an ESL 4’ out from the wall will have the rear wave arriving at least 8 to 10ms after the front wave) reflecting from side walls and front wall (between the speakers) is ‘time shifting’ the image by giving the ears these delayed cues that make the combined sound ‘appear’ at a point further behind the plane of speakers.

If this is not pleasant (and I sure don’t like it), I‘d suggest a strong dose of absorption and see what that does to your imaging. It will definitely move the image perceptibly forward.

 

[Jimna]

Jonathan i always enjoy your posts.

so in this situation your heavy dose of absorption is referring to the front wall? also along the lines of absorption and dipoles, what treatment to the ceiling would you use?

 

[kach22i]

Sleepysurf.........
The reason that such a large reflective surface between these speakers has minimal impact, is simply due to the dipole nature of electrostatic panels.

It's good to be reading something like this. I'm holding off on buying a flat panel TV for many reasons. My current situation including the last 12 years (CRT in the middle) will continue for some time.

(remember, an ESL 4’ out from the wall will have the rear wave arriving at least 8 to 10ms after the front wave)...........
..........I‘d suggest a strong dose of absorption ....... move the image perceptibly forward.

Could one also just move the speakers closer to the wall? My original Aerius speakers are only 30" out (as measured to the front face) because of room/wife restrictions.

 

[daveneumann]

After reading some of your posts and responses to the thread on imaging and power conditioners, I tried my system with the amp plugged directly into the wall. I had the amp plugged into an Adept Response 6, which is not supposed to be current limiting. However, with the amp plugged directly into the wall outlet (PS Audio outlet), things are more alive, there is greater leading edge transients and better dynamics, and slightly better detail retrieval. Most importantly, the center image is less recessed; it is still behind the plane of the speakers but seems to stand out more as do all images whether centered or not. The only price I pay is a very slight upper midrange hash/glare over loud complex passages. But it is well worth the trade-off.

Needless to say, the amp is staying plugged directly into the wall.

 

[Victor]

I conducted a recent test of the impact of a large HDTV placed between the speakers, and (not really that surprising) found out the impact is minimal (at least in my setup).

Sleepy.....not wishing to devalue anything you've set out to prove, your Test findings are not my experience at all.....indeed, regardless of how directional MLs are I'd be surprised if the slightest thing we did to a listening room didn't make an observable difference? My experiments were arguably more modest than this but one test I used was a simple pink noise generator from a surround receiver. The phantom centre voicing was audibly incongruous with the Left/Right channels but was "made uniform" by rotating the TV just a few degrees off axis (i.e. even listeners who were blindfolded & drunk would have instantly noted the effect). Most importantly, the difference in normal listening was a strong like/dislike issue on centre vocals depending on how well harmonised left, right and centre were.
Perhaps the reason is that we are acclimatised to the sound of our own systems and when something goes "out of tune" or is not to our taste we instantly notice it. I've always had difficulty with listening tests in which I have no ownership/emotional involvement of the system under review. There are a few high profile blind tests which have been conducted which prove the seemingly impossible e.g. that cheap systems are preferred to expensive high-end systems.
(You may have seen this before ? Go to blind tests and click on the link)

http://www.matrixhifi.com/ENG_marco.htm

The upshot of this is that if listeners are incapable of deciding on the merits of 2 completely different systems (speakers excepted), how much more would listeners struggle with a bit of ML tweakery ???

Kind regards...................................Victor.